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UMC Response <br />The hydrostatic head on the geomembrane liner will be less than two feet. UMC will continuously decant <br />the water for reuse in the mill to minimize makeup water requirements. Typically, tailings will be laid <br />down in a bench, or splay within the impoundment and a barge mounted decant sump pump(s) located at <br />the lowest level will pump the water back to the mill. This pump(s) will be pressure sensor activated (or <br />float switch activated). <br />CDRMS question <br />11. The Applicant has stated 4,500 yd of fill from the existing TSF OB stockpile. Please clarity if <br />this material was generated from the construction of the current TSF. <br />UMC Response <br />The referenced 4,500 yd is the excess cut material stockpiled from the original TSF construction. This <br />material will be incorporated into the cut and fill balance for the new TSF construction. <br />CDRMS question <br />12. The Applicant has stated the existing on -site stockpiles will also be initial feed stock for the mill <br />startup. Please verify that the existing on -site stockpiles are the same ones identified during the <br />Division's inspections conducted on June 18, 2009. <br />UMC Response <br />The referenced stockpiles are the same on -site stockpiles identified during the Division's inspection <br />conducted on June 18, 2009. <br />CDRMS question <br />13. In accordance with Rule 6.4.21(15) a detailed schedule for installation of the tailing <br />impoundment liner is required. The schedule is primarily needed for the Division to schedule <br />inspections of the Construction. Rule 7.4.2(2) identifies activities which will require phased <br />construction inspections. <br />UMC Response <br />The proposed construction schedule for the TSF follows. Reference the response to Question 5, QA/QC <br />plan for additional details on the listed activities. <br />General Site Preparation 2days No inspection <br />Clearing, Grubbing/Topsoil Removal /Storage 10days CDRMS inspection <br />Impoundment Excavation/Embankment Construction 5days CDRMS inspection <br />Clay Material Segregation/Clay Liner Construction 3days CDRMS inspection <br />Leak Detection /Sump Construction 2days CDRMS inspection <br />Impoundment Liner Installation 3days CDRMS inspection <br />Geotextile Liner Installation ldays CDRMS inspection <br />Overliner Material Placement, Slope Ballast Installation 5days CDRMS inspection <br />Tailings Slurry Piping, Decant Water Pumps 5days No inspection <br />M1990 -057 September 16, 2011 <br />